The speed of data transmission has increased. New specifications for the performance of modular plugs and jacks reflect the need for higher speed transmission without signal degradation. RJ45 modular plugs and jacks, not originally designed to perform at these levels, must be redesigned to meet the new, ever-increasing performance requirements based on existing infrastructure. While the outline and dimensions of the modular connectors are subject to the U.S. and international standards such as IEC 60603-7 series and TIA 568 series, the internal designs of plugs differ widely. The internal designs are intended to make the plugs satisfy the high speed application requirements.
Presently, the RJ45 connectors are used in applications from 30 KHz to 500 MHz. There are very few modular plugs known that can be used for high speed applications that consistently meet all the major transmission parameters and at the same time are easy to manufacture at low cost and can be used with a variety of cables.
Connector performance is judged by either direct measurement of the transmitted signals or more commonly, by controlling the major transmission parameters such as NEXT, Return loss, Common mode noise and Common to Differential mode conversion. These parameters are specified in the U.S. in TIA 568-10 and internationally in the IEC 60603-7 standard series. The high performance connectors are referred to by categories where category 5e is characterized by applications up to 100 MHz, category 6 by applications up to 250 MHz and category 6a by applications up to 500 MHz. There are several approaches to meet CAT6 and CAT6a performance levels in modular plugs and patchcord assemblies.
The simplest plugs utilize the direct attachment of the plug contacts to the wires without any means to control or modify the position of wires or electrical properties of the assembly. To use these, assemblers must posses a high level of skill and experience to ensure that the conductors are routed correctly. Minor differences in cable handling, pair twisting, foil shield location and wire location can make the difference between cable assemblies that pass or fail the performance requirements. While this design may achieve category 5e or 6 levels, it will not meet such levels consistently and will rarely meet Category 6A performance requirements.
More complex plug designs incorporate printed circuit boards that are used to rout the signals. These designs contain more components and are more expensive to manufacture and assemble. The performance of the PCB plugs is more consistent than the simple plugs noted above. This design can meet CAT 6A, but is very expensive.
There are no designs known that would improve the EMI performance when mated with unshielded jacks.
Thus, a need exists for a modular connector plug which satisfies CAT 6A requirements with improved Near End Cross Talk, Return loss and Common Mode Noise transmission parameters.